There is a demand for adhesives, especially of the kind used for cementing or sizing cardboard and paper, with an increased dry solid weight content and good storage stability. An increased dry solid weight content will not only result in faster curing rates but also leads to reduced water uptake by the substrates to be cemented. Typically, fillers are added to increase the dry solid weight content. However, these fillers reduce the "wet tack" and the curing rate. Moreover, such formulations often are not storage stable at ambient temperature and have a too high viscosity for normal processing. The poor storage stability typically manifests itself in the floating out of one or more of the ingredients. In the case of known water glass-dextrin products, very often the dextrin floats out. Also, the use of solid fillers in the formulation is less desired, because such a solid, especially when used in a high quantity, may settle during storage and because it may affect the equipment. Since it often is an abrasive, it may for instance cause an increased wear of the pumps.
Moreover, there is a need for cemented articles with a higher crush value than is presently obtained when, for instance, plain water glass is used as the adhesive. Such higher crush values will allow the use of thinner-walled articles, with attendant savings.
Therefore, there is still a need for new water glass based adhesive compositions with improved properties.
It is noted that U.S. Pat. No. 3,767,440 discloses a composition comprising water glass, dextrin, and a clay slurry. It is stated that known formulations containing water glass and more than 0.5% of dextrin, as in, for instance, U.S. Pat. No. 3,343,691, are not storage stable. This reference teaches to use 4.5-12 % by weight of a clay slurry in the formulation to improve the storage stability. As mentioned above, such a high qauntity of a solid filler is not desired. It is not disclosed or suggested to use a composition comprising a mono-, di- and/or tri-saccharide to improve the performance and the storage stability.